Project Abstract/Summary Diabetes currently affects 9.3% of the U.S. population totaling $245 billion annually in U.S. healthcare costs. Current therapies for diabetes are limited in their ability to control blood glucose and/or enhance insulin sensitivity. Given the magnitude of diabetes costs and complications, new therapies with reduced side effects are urgently needed. The common defect in both type 1 and type 2 diabetes is the loss of functional pancreatic islet ?-cell mass. A therapeutic intervention that replenishes the insulin-producing pancreatic beta cells represents a cure for diabetes We propose to develop two distinct molecular scaffolds with demonstrated in vivo proof of concept for stimulating pancreatic beta-cell proliferation. A series of phenylbenzamides, discovered in an unrelated hepatic steatosis screen, were found to stimulate selective beta cell proliferation in rodents, isolated rat and human islets, and will be evaluated and optimized for efficacy and translational potential. The second series - chromenones, discovered in a Nkx6.1 promoter screen, have been shown to robustly stimulate beta-cell proliferation in rodent and human islets. We will perform medicinal chemistry optimization on both scaffolds to produce in vivo chemical probes with translational potential for human therapeutic use.